It has been proposed to improve the eye appeal of certain food products such as processed meats by providing the food product with surface ornamentation such as a logo, design or other decorative pattern. For example, eye appeal of skinless sausages, such as frankfurters and the like, is improved by marking the surface to simulate the burn mark pattern caused by grilling the sausage. In one method, the application of the so-called "grill marks" is accomplished by passing the frankfurters over hot wires to brand them. However, this method has not been widely adopted by the meat packing industry.
Casings most commonly used for manufacturing encased food products such as processed meat articles comprise relatively long, thin-walled tubes of regenerated cellulose prepared by extruding and then coagulating a viscose solution. Cellulosic casings of regenerated cellulose are either reinforced with a fibrous web (hereinafter "fibrous casing") or unreinforced. Unreinforced casing generally is used in preparing smaller diameter products such as frankfurters and the like whereas fibrous casings are used in preparing larger diameter products such as bologna and hams.
For convenience in handling, the casings, which may be twenty to seventy meters or more in length, are shirred and compressed to produce what are commonly referred to in the art as "shirred casing sticks." These sticks, which measure about twenty to seventy centimeters in length, may contain upwards of 70 meters or more of casing. processes for manufacturing cellulosic casings and for subsequently shirring them to produce the shirred sticks are well known in the art and will only be described herein in sufficient detail to facilitate an understanding of the present invention.
Utilizing the casing to apply markings to the surface of a sausage has been attempted. For example, in U.S. Pat. No. 2,301,564 an aniline ink is printed on the outside of the casing. During sausage processing operations subsequent to stuffing the ink permeates and passes direct)y through the casing wall to the surface of the sausage meat. The '564 Pat. indicates that a clear outline of the markings are reproduced on the sausage surface. However, it is not believed that the clarity of the marking on the sausage surface will satisfy commercial requirements for sharpness and clarity. For example, tests conducted with conventional water soluble food dyes such as U.S. Government approved food, drug and cosmetic dye Red 40 (molecular weight about 400) were successful in that a pattern of grill marks printed on the outer surface of the casing passed through the casing wall and indelibly transferred to a frankfurter made by stuffing and processing a frankfurter emulsion within the casing. However, the diffusion of a-low molecular weight water soluble dye such as Red 40, through the casing wall disperses the dye. The result is that the pattern transferred onto the food product is not as sharp and distinct as the pattern initially printed on the outer surface of the casing. Also, the dye tends to diffuse into the body of the frankfurter which further decreases the sharpness and distinctiveness of the transferred pattern on the surface of the frankfurter. Certain other known coloring materials, such as liquid smoke and synthetic brown dyes, have the same difficulty.
Accordingly, an object of the present invention is to provide a food casing having indicia on one surface thereof which is substantially nondiffusible into the casing and which is indelib1y transferable to a food product stuffed into the casing in contact with the surface.
Another object is to provide such a casing in which the indicia is composed of a material which remains on the casing surface to which it is applied and subsequently transfers from that surface directly onto the surface of a food product stuffed into the casing and in contact with the casing surface.
Still another object is to provide such a casing wherein the indicia forms a pattern of grill marks which are transferable to the food product.
A yet further object is to provide a method for making such a food casing.
A still further object is to provide a skinless food product having surface ornamentation derived from indicia located on a casing surface in contact with the food product, and to a method for making such a food product.
In the present invention, the casing used in the manufacture of the encased food product is provided with means for imparting a clear, sharp image of an ornamentation, logo or other desired indicia to the surface of the product processed within the casing.
In this respect, one surface of the cellulosic casing is provided with indicia in mirror image to the pattern desired on the surface of the food product. During stuffing, the casing surface carrying the indicia is brought into direct contact with the food product stuffed into the casing. The indicia material comprises an edible material which releases from the casing surface and transfers to the surface of the food product so that after stuffing and processing a mirror image of the pattern remains on the surface of the product when the casing is removed.
To be effective, the indicia on the casing surface should comprise a coloring material that provides a distinct, sharp pattern. Casing manufacturing and shirring operations performed after application of the indicia material to the casing should not smear or distort the indicia. Otherwise, the pattern, when transferred to the processed sausage, is blurred and/or distorted. The indicia material may be applied in-line during the production of the casing. If this is done, the indicia material must remain on the casing during subsequent handling of the casing including shirring of the casing to produce the shirred stick and the eventual despairing of the casing to stuff it. However, the indicia material should be releasable from the surface of the casing on stuffing and/or processing so the indicia can transfer to the surface of the food product in contact with the casing.
The indicia material should lie on the surface of the casing on which it was applied and should not diffuse or otherwise substantially penetrate into the casing wall. This will insure that substantially all of the indicia material is available for release and transfer to the food product within the casing, thereby providing as distinct a pattern as possible. It further is necessary for the indicia material to remain on the surface of the food as the casing is removed to make a skinless food product.
Application of the indicia material to the casing can be accomplished by any suitable means such as by stenciling, spraying or printing. A printing operation is preferred and will be described further herein below. For purposes of printing, the indicia material must be transferable from the printing plate and onto the casing surface.